The extent of the injury is as yet unknown but the good news for Gatland and co. is the flanker was sitting up in the home dressing room at half time.
On the field Ospreys laboured to the bonus-point win despite wing Richard Fussell opening the scoring for the Welsh region with a try in the seventh minute.
The home side made heavy work of things from then on and had to wait until the 65th minute for the first of two penalty tries won by a dominant scrum which put them on the way to a commanding win.
Lee Byrne and Ireland international Tommy Bowe rounded off some flowing running to put the icing on the cake and ensure the Ospreys made the most of their home fixture against the Italians.
Aironi were limited to two penalties from fly-half Riccardo Bocchino and the Italians rarely threatened the Ospreys' line.
Fly-half Dan Biggar was impressive with the boot landing five out of five conversions while he also kicked two penalties to end the game with 16 points.